1. Field of the Invention
The present invention relates to a method for controlling the washing operation of a washing machine, and more particularly, to a method for controlling the washing operation of a washing machine capable of changing washing conditions according to the change in temperature of washing water, so that the optimal washing effect is achieved.
2. Prior Art
FIG. 1 shows a conventional washing machine, which shows a drum type washing machine. The drum type washing machine has a body 1, a tub 2 supported in the body 1 by a suspension and a shock absorber which are not shown, and a drum 3 installed in the tub 2 to be capable of rotating. A plurality of dehydration ports 3a and protrusions 3b are formed on the inner side of the drum 3.
A driving device 5 for driving the drum 3 is installed one side of the tub 2, and a draining device 7 for draining washing water in the drum 3 after the washing operation has completed is provided under the tub 2. A heating device 9 for heating the washing water in the drum 3 is installed at the upper side of the tub 2, and a door 8 for opening/closing the tub 2 is installed on the front side of the body 1.
Meanwhile, a water supply device 6 for supplying the drum 3 with water used for washing is installed in the upper area of the body 1. A detergent supplier 4 having a detergent container 4a is installed in front of the water supply device 6. On the upper front area of the body 1, a control panel 10 is provided, through which a user controls the operational status of the washing machine.
The operations of the washing machine consists of a washing operation, a rinsing operation, and a dehydrating operation. In order to perform the washing operation, the user opens the door 8 and puts laundry into the drum 3, and then utilizes the control panel 10. A microprocessor (not shown) in the washing machine controls the operation of the washing machine according to the input to the control panel 10 given by the user.
In more detail, the water supply device 6 and the detergent supplier 4 supply washing water and detergent into the drum 3. As the drum 3 is rotated by the driving device 5, the washing operation is performed. That is, as the drum 3 is rotated, the laundry in the drum 3 is raised by the drum 3 and then is dropped. The washing operation of the detergent is performed by the impact applied to the laundry in such a situation. The drum 3 is rotated in forward and reverse directions alternately. Meanwhile, in order to perform the washing operation with hot water, the heating device 9 operates while the drum 3 is rotated.
FIG. 2 shows the process for performing the heating-washing operation of the conventional washing machine. When a user sets S101 a time and a temperature through the control panel 10, the washing machine performs heating operation S102 during the washing operation.
A sensor (not shown) in the washing machine measures S103 the temperature of the washing water. The microprocessor judges S104 whether the measured temperature is higher than the set temperature or not. If the measured temperature is lower than the set temperature, the washing and heating operations are performed continuously, and if the measured temperature is higher than the set temperature, the washing and heating operations are stopped S105.
The washing operation continues while the heating operation is stopped, and the microprocessor measures S106 the time that the washing operation is performed. If the measured time reaches S107 the set time, the washing operation ends.
After the heating-washing operation has been completed, the washing water is drained from the tub 2 by the draining device 7, and thereafter, the rinsing operation consisting of supply of water, rinsing, and draining is performed. After the rinsing operation has been completed, the washing water is drained again by the draining device 7, and then the dehydrating operation is performed. The drum 3 is rotated at a high velocity during the dehydrating operation, and the laundry is dehydrated by the centrifugal force generated by rotating drum 3.
However, in such a conventional method for controlling the heating-washing operation, a simple washing operation is continuously performed while the washing water is heated, irrespective of the variation of the temperature, so there is a shortcoming that the washing effect is not maximized. In order to improve the washing effect, it is preferable that the washing machine is driven according to an optimal operational condition corresponding to the temperature of the washing water.
Furthermore, in the conventional method for controlling the heating-washing operation, the heating operation is performed after the entire amount of washing water set by the user has been supplied, so the time consumed until the washing water reaches the set temperature is long, and thereby washing efficiency is lowered. Moreover, in such a situation, the washing operation is performed while the washing water is at a low temperature before it reaches the set temperature, so the washing operation is performed with the washing effect being insufficient, which may also result in low energy efficiency.